63O COMPOSITAE 



37. Galinsoga R. & P. 

 1. G. parviflora Cav. In door yards and waste places: eastern 

 Mass. to Ore., N. Car., Kan. and Mex. Naturalized from 

 tropical America. 



Common as a weed everywhere, often replaced by the form 

 known as hispida D.C. 



G. caracasana (DC.) Sch. Bip. has been found in waste grounds in N. J. 



Tribe 6. Helenieae 

 Consists, in our area, of only the following genus: 



38. Helenium L. 



Stem-leaves oblong-lanceolate or ovate-lanceolate, dentate; rays 



fertile; disk yellow. I. If. autumnale. 



Stem-leaves lanceolate or linear-lanceolate, mainly entire; rays 



neutral; disk purple. 2. H. nudiflorum. 



1. H. autumnale L. In swamps and wet meadows: Que. to 



Conn., Fla., S. Dak., Kan. and Ala. 

 Throughout the range, except in the pine-barrens, there unknown. 



2. H. nudiflorum Nutt. In moist soil: Kan. to 111., Tex., east 



to N. Car. and Fla. Adventive eastward. 



Rare as an occasional adventive in parts of our range. 

 II. tenuifolium Nutt. and //. guadridculaliiiii Labill. have been collected as waifs. 



Tribe 7. Anthemideae 



Receptacle chaffy. 



Achenes flattened; involucre obovoid to campanulate; 



heads small. 39. Achillea. 



Achenes terete; involucre hemispheric; heads large. 40. Anthemis. 



Receptacle not chaffy, naked, or sometimes hairy. 



Ray-flowers usually present, sometimes wanting; rays large. 



Bracts of the involucre in several series. 41. Chrysanthemum. 



Bracts of the involucre in few series; rays white or 

 none. 42. Matricaria. 



Ray-flowers none; heads small. 



Head-; corymbed; pappus a short crown; flowers 



yellow. 43. Tanacetum. 



Heads racemose, spicate or panicled; pappus none. 44. Artemisia. 



39. Achillea [Vaill.] L. 



Leaves serrate. 1. A. Ptarmica. 



Leaves finely dissected. 



Rays 3-6 mm. broad; plant villous; achenes broadly margined. 2. A. lanulosa. 



Rays 2-3 mm. broad; plant sparsely villous or glabrate; achenes 



scarcely margined. 3. .4. Millefolium. 



